|
|
Product : PM1000+
Item Under Test : small SMPS as USB chargerQuestion : Further to my question earlier about PF..... When we are using the PM1000+ to measure the (small) input current to the USB charger running at no load, the input current shown up as around 1mA rms. We tried with the USB charger removed from the test wires, and/or with the two current sense leads shorted, the current shown is around 0.9mA+. So there is an offset of close to 1mA rms on the meter alone even the current sense leads are shorted! Is there something wrong with our meter?
|
| |
|
|
 | |
|
|
Dear Ram,
This is normal for the PM1000+. It has a specification that is +/- 1mA. This is mainly due to random noise so you will find that the power specification is much tighter. Noise does not contribute much power because it is not in phase or synchronised to the voltage. Please select the standby power mode when measuring these types of equipment (that do not draw steady state currents) to get accurate readings.
Best regards,
Tim.
|
| |
|
|